1. Field of the Invention
The present invention relates generally to a movable door for selectively covering an opening in a wall, and more particularly to an improved egress assembly in the movable door for allowing passage therethrough when the wall opening is covered.
2. Discussion of the Background Art
A "labeled" door assembly is defined by the National Fire Protection Association as a combination of a door, hardware and other accessories which together provide a specific degree of protection to an opening when closed and to which has been attached a label or other identifying mark to indicate compliance with nationally recognized standards or tests. Conversely, all other door assemblies are referred to as "non-labeled" door assemblies.
For emergency egress purposes, various building codes and the like require any building having either a slide-type or rolling type door assembly to include both a fire door positionable to close an opening and a hinged-type wicket or pass door for passage therethrough when the opening is closed by the fire door. In some cases, compliance with the above requirement may be achieved merely by providing the pass door in the wall of the building adjacent the fire door. Alternatively, a pass door may be incorporated into the movable fire door itself. In U.S. Pat. Nos. 4,217,731 and 4,461,120, for example, there are shown fire door assemblies which include a single hinged pass door in a sliding fire door for allowing passage through the sliding fire door. As will be readily appreciated, however, sliding fire doors may be unattractive to building designers because of the need to provide adjacent wall space to accommodate them. This same need for adjacent space may also complicate or frustrate efforts to retrofit a sliding door over an existing opening.
In an effort to avoid the space problems and other disadvantages associated with slide-type door assemblies, rolling door assemblies, which include a shutter curtain that is raised or lowered from a roller positioned above the opening, have been developed. Typically, two vertically disposed channels are positioned adjacent opposite lateral sides of the opening to guide the shutter curtain as it is retracted or extended between the opened and closed positions.
While a service door configuration is known in which a pass door frame is hingedly connected to a vertical, shutter guide channel to provide passage when the rolling curtain service door is closed, this configuration utilizes a door frame structure that must be manually positioned and locked prior to extension of the shutter curtain. As such, this configuration can not be utilized in self-closing fire door applications in which the rolling door is closed automatically, such, for example, in response to detection of a fire.